Hey All,
My 2005 super V8 started having an overheat problem on a recent two hour trip from columbus ohio to cleveland. If I kept the car below 70 the temp moderated a bit but even slight uphills made the temp go immediately to red. Somehow I limped home in cooler temperatures at night, but the same scenario existed. Over the next two weeks the low coolant warning came on, then finally, after taking it to my shop where a system flush and new coolant were done, I actually had coolant left on the garage floor after a short trip.

Took it again to my shop, where he identified an easy to reach bypass hose leaking. He changed it, but this did not solve the problem.The shop let the car idle for an hour, but when I drove it home it took only 15 minutes to overheat.

Back to the shop and further digging by taking the top off the engine showed where the problem was.

Since he had to take the top of the engine off and then had access to other things, he replaced 4 bypass hoses, the thermostat, engine gaskets, the o-rings on the fuel injectors, the fuel filter, and did another flush of the coolant system. I think he said there was another main hose under the engine that he replaced but not sure.

Anyway, for all this he charged me $500. The car is running really well, and as one might expect, has a bit more pep than before.

One interesting thing about all this was that he said the first bypass hose could only be sourced from Jaguar, and it too forever to arrive. Since I'm really patient with the process and trust the shop I go to, I think they cut me slack on the price of repairs. They are really good people even though they think my car is for an old lady.

Later,
Mike D.
2005 Super V8

 

Your very lucky, from what i've read, it's often too late, when it goes into the red.

 

Wingrider -
Thanks for the reminder - I did my best not to push it, and as soon as red showed, I managed to find a way to keep the temperature below the danger zone. It could have been otherwise, or something more serious and disappointing like a head gasket.

I am also lucky in that a non-wrencher like me has a reasonable and experienced mechanic to service the car.

I learn a lot from your hard work and I appreciate the posts.

Mike D.

 

This was also just mentioned in another thread (https://www.jaguarforums.com/forum/x...sensor-217919/), the plastic coolant housings on these engines are known to deteriorate internally. When this happens hot engine coolant recirculates back through the block instead of going into the radiator. Only way to tell is to pull the thermostat and visually inspect. These housings only last about 50k miles.

 

Thanks for that! Work to do here...

I had "re-engineered" the OEM ziggy-zaggy top hose with the multiple molded-in right angle bends to a simpler, long sweeping curve some years ago.

Even so, of a late night last week still had to pull off I-66 when the temp indicator went way LOW, then pounced up against the top stop, red overheat came on.

Engine was barely warm, miniscule trapped vapour escaped when bled at header-tank inlet, Coolant level normal. Ran OK on home, Did more bleeding and top up next day. Fine since.

Per the records, my motor had been replaced, outright, under warranty for a previous owner. It NOW has right about 60-65K miles on it, so...

 

When my one did so, I applied an old FIAT trick: Opened the windows (and sun roof) kicked the heater on HIGH, max fan.

Seems to have saved the day (yet, again..) until I could mosey off an exit ramp and find a safer place to get the bonnet up.

 

Taking the cap loose before driving helped the old cars from building pressure to run cooler.